Visible Light-Assisted Bacterial Inactivation of Halogen/Nitrogen Co-Doped Polymeric Graphene Quantum Dots

• Main Authors: Huang, Hao-Hsin, 黃皞心
• Other Authors: Huang, Chih-Ching
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/ez45wf

碩士 === 國立臺灣海洋大學 === 生命科學暨生物科技學系 === 107 === In this work, we have developed visible light activated halogen/nitrogen co-doped polymeric graphene quantum dots (HX/N–PGQDs, (X= Cl, Br, I)) as antibacterial agent, by a simple one-step synthesis method. Microbial contamination due to bacteria and fungi poses serious threats to human health and has presented an unprecedented new challenges to antibacterial research for many years. The major challenge is the evolution of drug resistant bacteria, which are evolving faster than previously anticipated. With the recent advancement in nanotechnology, much progress has been achieved in the development of antimicrobial nanomaterial. However, these nanomaterials based antibacterial agents still suffer from potential biological toxicity. CQDs have become a rising star owing to their excellent fluorescent properties, high biological toxicity, and low cytotoxicity as effective visible-light photocatalysts and antimicrobial nanomaterial for oxidation and reduction reactions. Halogen-based antibacterial agents are known to prevent lethal diseases from infectious pathogens and therefore have attracted significant research interest. Here, we demonstrate that HX/N–PGQDs are effective antibacterial agents for the inhibition of both Gram-positive and Gram-negative bacteria in a concentration dependent manner. The antibacterial activity of HX/N–PGQDs is enhanced upon exposure to light irradiation. The minimal inhibitory concentration (MIC) of HX/N–PGQDs in ambient light condition is 100-fold lower than those of HX/N–PGQDs without light, demonstrating their strong photo-induced bactericidal functions. In addition, HX/N–PGQDs prepared at 270 °C for the tested bacteria (E. coli) are shown to have much lower MIC values than those of prepared at 240°C. We believe that HX/N–PGQDs has great potential as a visible light-activated antibacterial nanomaterial for preclinical application in wound healing.